[Checkins] [zopefoundation/BTrees] a7b7ea: Python/C OO consistency

[GitHub]

  Branch: refs/heads/issue51
  Home:   https://github.com/zopefoundation/BTrees
  Commit: a7b7ea11f9260d3ae207ca79c4f4cebef553ffd3
      https://github.com/zopefoundation/BTrees/commit/a7b7ea11f9260d3ae207ca79c4f4cebef553ffd3
  Author: Jason Madden <jamadden at gmail.com>
  Date:   2016-12-22 (Thu, 22 Dec 2016)

  Changed paths:
    M BTrees/_base.py
    M BTrees/tests/test_OOBTree.py
    M CHANGES.rst

  Log Message:
  -----------
  Python/C OO consistency

Check key identity before ==. This matches the C implementation.
Fixes #50

Add a pickle test to the work done in #54. Fixes #51. Fixes #53 (for
Python 2).